The present invention is directed to couplings, and more particularly, to couplings which are capable of both coupling objects together and uncoupling the objects easily and quickly.
It is usually important in couplings that the objects to be coupled together by the coupling are securely coupled so that the possibility that the objects may inadvertently become separated in use is eliminated. For example in resilient stretchable exercise devices, it is important that the loops or hand grips which are to be grasped by the person exercising are securely coupled to the stretchable resilient component or components to eliminate the possibility that these may inadvertently come apart during use and cause possible injury to the user. It is also frequently advantageous for example in such exercise devices if the component parts may be easily and rapidly coupled together and also easily and rapidly uncoupled, and that these functions may be accomplished without the need for tools or complicated procedures. It is also important that the coupling can be easily handled, is streamlined in design without projections or protrusions that may catch on clothing or the like, and be economical.
The coupling of the present invention achieves all of these aforementioned desired advantages. In a coupling of the present invention two coupling elements may be easily and rapidly snapped together, and when they are snapped together, they are securely coupled to each other without the possibility of inadvertent separation during use. However, even though the two coupling elements are securely coupled in use, they can be easily and rapidly separated from each other simply by rotating them relative to each other, and when they are so rotated, they actually pop apart.
In one principal aspect of the present invention a coupling for coupling two objects together includes a first element which is adapted to have one of the two objects attached thereto. This first element comprises a shaft having a given cross-sectional dimension, and a shoulder extending from the shaft such that the shoulder together with the shaft have a cross-sectional dimension greater than the given cross-sectional dimension of the shaft. The coupling also includes a second element adapted to have the other of the two objects attached thereto. The second element includes a sidewall having first and second openings and defining a cavity for receiving the first element therein by insertion of the shaft and shoulder of the first element through the first opening with the shaft extending from the second opening. The sidewall also has a shoulder which overlies the shoulder on the first element when the first element is inserted in the cavity to prevent removal of the first element through the second opening. A portion of the first opening is defined by the shoulder of the second element, and the portion of the first opening which is so defined has a width somewhat smaller than the given cross-sectional dimension of the shaft. At least one of the first and second elements includes a flexible portion so that as the first element is inserted into the cavity, the flexible portion flexes to permit passage of the shaft past the portion of the first opening defined by the shoulder of the second element. The coupling also includes a cam on the first element which cooperates with the second element when at least one of the elements is rotated to cause the first element to be discharged from the cavity to separate the first element from the second element.
In another principal aspect of the present invention, the aforementioned first opening of the second element includes the flexible portion to permit passage of the shaft.
In still another principal aspect of the present invention, the aforementioned flexible portion of the first opening flexes to permit passage of the shaft when the first element is being inserted into the cavity and to hold the shaft against removal from the cavity once the first element has been inserted in the cavity, and the flexible portion of the first opening also flexes when at least one of the elements is rotated to cam the first element from the cavity.
In still another principal aspect of the present invention, the aforementioned flexible portion is plastic.
In still another principal aspect of the present invention, the first and second elements are plastic.
In still another principal aspect of the present invention, the aforementioned overlaying shoulder of the second element adjacent the first opening has a flat surface which frictionally engages the shaft as the shaft moves through the first opening.
In still another principal aspect of the present invention, the shaft of the first element and the sidewall of the second element are substantially cylindrical.
In still another principal aspect of the present invention, the aforementioned cam is on the shoulder of the first element.
In still another principal aspect of the present invention, the cam extends beyond the cross-sectional dimension of the shoulder of the first element.
In still another principal aspect of the present invention, the aforementioned cam cooperates with said first opening on said first element to cause said first element to be discharged from said cavity.
In still another principal aspect of the present invention, the first element is prevented from insertion of the cam through the first opening into the cavity preferably by a pin which extends beneath the shoulder of the first element.
In still another principal aspect of the present invention, the aforementioned coupling includes a flexible stretchable resilient member attached to the first element, and a loop attached to the second element whereby the coupling is part of an exercise device.
In still another principal aspect of the present invention, a coupling is provided for a flexible hollow tube comprising a first element which includes a shaft having an opening extending axially therethrough, the width of the opening at one end of the shaft being smaller than the width of the opening at the opposite end of the shaft. A hollow flexible tube having an exterior width which is less than the width of the opening at the one end of the shaft has an end which is positioned in the shaft so that the tube extends from the opening at the one end of the shaft. A ball-shaped member is inserted in the end of the tube within the shaft and expands the exterior width of the tube to a width greater than the opening at the one end of the shaft to prevent the end of the tube within the shaft from passing through the opening in the one end of the shaft.
In still another principal aspect of the present invention, the aforementioned ball-shaped member includes a stem which extends therefrom toward the end of the tube, and a clamp is positioned about the exterior of the tube clamping the tube to the stem to prevent the tube from separating from the ball-shaped member.
These and other objects, features and advantages of the present invention will be more clearly understood through a consideration of the following detailed description.